Air floated grinder



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2,992,520 AIR FLOATED GRINDER Paul Kish, San Fernando, Calif. (6735Elmer St., North Hollywood, Calif.) Filed June 2, 1958, Ser'. No.739,203 1 Claim. (Cl. 51-166) This invention relates to an air floatedgrinder and has for one of its principal objects the provision of adevice of the class described which, while being portable, is at thesame time capable of accurately performing a great variety of diflicultgrinding and similar operations.

One of the important objects of this invention is to provide a grindingmachine which is driven by compressed air and wherein the exhaust air isemployed to maintain the grinder in a position for portable manualoperation and an actual elimination of the weight of the same.

Another important object of the invention is to provide a portable airsupported grinding apparatus which will be adjustable in severaldimensions, thereby making the same available for very accurate workwithout, in any way, interring with the resultant efliciency.

Yet another object of the invention resides in the provision of amachine tool which can be employed for purposes other than grinding andwhich will, during all operational periods, be supported on a cushion ora layer of air, thereby providing considerable mobility and eliminatingany possibility of tiring the operator, even over long periods ofworking time.

Other and further important objects of the invention will be apparentfrom the disclosures in the accompanying drawings and followingspecification.

The invention, in a preferred form, is illustrated in the drawings andhereinafter more fully described.

In the drawings:

FIGURE 1 is a side elevation, substantially wholly in section, showingthe improved air floated grinder of this invention.

FIGURE 2 is an enlarged vertical section, taken on the line 2-2 ofFIGURE 1, looking in the direction indicated by the arrows.

FIGURE 3 is a reduced plane view, partly broken away, taken on thehorizontal line 3-3 of 'FIGURE 1, looking downwardly.

FIGURE 4 is a partial vertical section on the line 44 of FIGURE 1,illustrating additional details.

FIGURE 5 is an enlarged section on the plane of the line 55 of FIGURE 1,looking in the direction indicated.

FIGURE 6 is an enlarged view, partly in section, illustrating a portionof the structure shown in FIGURE 1, but with a slight modification.

FIGURE 7 is a section on the line 77 of FIGURE 6.

As shown in the drawings:

The reference numeral 10 indicates a base plate upon which the uprightor supporting standard 12 of the improved grinder of this invention ismounted by means of bolts or the like 14.

Beneath the plate 10 and in spaced relation thereto over practically allof its area, is a perforated plate 16 which also forms part of thesupporting base and which is fastened to the plate It} about theirjuxtaposed peripheries by machine screws or the like 18. It will benoted that the plate 16 is internally recessed, as best shown at 20 inFIGURES 1 and 3, with a number of perforations 22 all over and throughthe recessed area.

The motive power for the grinder is furnished by means of an air driventurbine 24 of any preferred or representative type. Compressed air foroperating the same is brought in through a hose 26, control valve 28 andpipe 30. The air is exhausted from the turbine 24 and through a pipe 32which leads downwardly through the supporting Patented July 18, 1961stand 12 and exits through an opening in the plate 10, all as best shownin FIGURE 1.

This exhaust air enters the space 20 between the plates 10 and 16,diffuses itself throughout and exits through the numerous, evenly spacedand properly distributed openings 22. This results in raising thesupporting base Ill-16 slightly above the surface 34 which may be aplane table, bench, part of a machine or anything similar. Thiselevation of the entire apparatus: is very, very slight, usuallymeasuring in tens of thousandths of inches which, therefore, will in noway detract from the accuracy of the work performed by the grinding toolor some similar device, as indicated at 36. Alternatively, the grindermay be used to smooth the surface of a piece of work 38, and thiselement 38 may comprise an integral extension of the support 34.

A housing 40 is provided for the turbine 24, and suitable bearingssupport a driving shaft 42 which extends through an extension 41 of thehousing 40 being supported by another bearing 44 in a secondary housing46. This housing 46 includes a tubular extension '48 which projects intothe open end of the housing 40, allowing for relative sliding motiontherebetween. This is adjusted by means of a thumb screw or the like 50,supported in integral extensions 52 of the housing 40 and operatingthrough a threaded element 54 which is fastened to the inner end of thesleeve 48, all as best shown in FIGURE 1.

It will be noted that the shaft 42 is splined at 56 to slidably interfitwith a similar internally splined tubular shaft 58. This is in turnsupported in the bearing 44 and by an auxiliary bearing 60 in the end ofthe tubular extension 48.

A bevelled gear 62 is fitted onto the end of the tubular shaft 58, andthis is in mesh with a similar bevelled gear 64 mounted on a verticalshaft 66, the upper end of which is in a bearing 68 supported by thehousing 46.

This shaft 66 is splined at 70 and interfits with an internally splinedshaft 72 mounted in a cylindrical housing 74 which can be moved up ordown in the lower end of the housing 46.

One means of accomplishing this adjustment is shown in FIGURE 4, whereina knurled adjusting screw 76 is fitted into an extension 78 of thehousing 46 with an internally screw-threaded element 80 riding on thescrew and contacted to the cylinder 74.

The lower end of the shaft 72 is recessed for the reception of a holdingchuck or similar device 82, whereby the tool 36 is adequately supportedfor proper operation.

Cover plates 84 and 86 are provided for the housings 40 and 46,respectively, and a sleeve 88 is interposed between the tubularextension of the housing 40, and the extension 48 for better and moreaccurate operation, all as best shown in FIGURE 6. This figure alsoillustrates a modified form of adjusting the relationship between thetubular elements which consists of a gear 90 operating on a rack 92,which rack is in turn fastened to the sleeve 48. The gear 90 is turnedby means of a knurled knob or the like 94, as best shown in FIGURE 7.

It will be evident that herein is provided a grinding tool which iscapable of an almost infinite number of adjustments, both outwardly fromthe source of power and also in a complete circle about the center ofoutward movement, it being obvious that the housing 86 can be readilyrotated through 360 about the longitudinal center of shafts 42 and 58.Also, the tool can be locked in this adjusted position by means of theset screw 96 which is in a boss 98 in the tubular extension 40 of theturbine housing.

It will also be evident that, due to the infinitesimal layer of exhaustair which supports the entire apparatus, the same can be readily movedover and about any supporting surface 34, regardless of whether thissupporting surface is merely a support or whether it actually is part ofthe work itself. This condition, of course, prevails only when asuitable level and plane surface. is employed, as indicated by thereference numeral 34.

A very great ease of operation with considerable accuracy results whileat the same time the adjustability enables satisfactory operation underalmost all circumstances and conditions Which might be encountered inwork of this type.

I am aware that many changes may be made and nuerous details ofconstruction varied through a wide range without departing from theprinciples of this invention; and I, therefore, do not propose limitingthe patent granted hereon otherwise than by the appended claim.

I claim as my invention:

An air floated grinder including a supporting base, said base comprisingtwo plates joined at their edges but spaced apart over a largepercentage of their interior area, a stand on the upper base plate, anair-turbine at the top of the stand, intake and exhaust lines forcompressed air in the stand, a splined driving shaft driven by the airturbine, a beveled gear at the outer end of said shaft, a telescopichousing for the splined shaft extending from the air-turbine, anotherhousing at the end of the telescopic housing, a beveled gear in the lastnamed housing in mesh with the first named gear, a second splined shaftconnected to the second beveled gear and extending through the secondhousing, a grinding tool at the end of the second splined shaft,bearings for the shafts in the respective housings, the operate face ofsaid grinding tool being substantially the same plane as the outer faceof the lower base plate, the compressed air outlet comprising a tubeterminating in the space between the two plates, the lower plate havinga series of perforations therein for exit of air therethrough, the lowerplate being confined to a single plane with a minimum variation and saidbase adapted to be moved over a similar substantial flat platformwithout actually contacting the same in operation, said compressed airturbine furnishing the motive power for the grinder through the splinedshafts, said compressed air outlet tube conveying exiting air from theturbine to the space between the base plates and out through theperforations to contact the platform.

References Cited in the file of this patent UNITED STATES PATENTS639,278 Patch Dec. 19, 1899 691,740 Birkenstock Jan. 28, 1902 2,288,646Ragsdale July 7, 1942 2,301,164 Mall Nov. 3, 1942 2,316,886 PascucciApr. 20, 1943 2,423,826 Cardone et al. July 15, 1947 2,671,700 SeyffertMar. 9, 1954 2,780,826 Coons Feb. 12, 1957 2,832,986 Seck May 6, 19582,869,933 Bessinger Jan. 20, 1959 OTHER REFERENCES Air LubricatedBearings by P. M. Mueller, published in Product Engineering, August1951; pages referred to 112 to 115, inclusive. (Copy in ScientificLibrary and Div. 45.)

